Collaborative Augmented Reality (AR) setups are becoming increasingly popular. We have developed a collaborative tabletop environment that is designed for brainstorming and discussion meetings. Using a digital pen, participants can annotate not only virtual paper, but also real printouts. By integrating both forms of physical and digital paper, we combine virtual and real 2d drawings, and digital data which are overlaid into a single information space. In this paper, we describe why we have integrated these devices together in a unique way and how they can be used efficiently during a design process.